Nowadays, one of the most important endeavors in the design of drive units for different purposes is the minimization of the demand for fuel in order to ensure the most effective and non-polluting operation possible of the drive unit. Depending on the respective purpose, however, the primary objective may also be a weight reduction, e.g., when the drive units are used in vehicles and, in particular, aircraft. In order to optimize the fuel demand in aircraft, it is currently common practice to utilize fuel cell systems for generating electrical power and thusly reducing the mechanical power to be generated by the main engines, part of which is used for driving electric generators.
The German patent application with file number DE 10 2011 018 448.1 describes a particularly advantageous drive unit, in which a highly compact integration and coupling of a fuel cell device and a combustion chamber is realized directly within an internal combustion engine. A fuel-air mixture flows through solid oxide fuel cells such that a fuel cell process is initiated within the fuel cells. The fuel-air mixture flowing through the fuel cells is only partially utilized in the fuel cell process. The unconsumed fuel-air mixture flows into a downstream combustion chamber in order to conventionally generate mechanical power.